A variety of passive vehicle occupant restraint belt systems have been proposed in which a restraint belt leads from an inboard location at the lower rearward portion of the seat across to the rear portion of the vehicle door so that when the door is opened, it carries the outboard end of the belt forward out of engagement with the occupant. Some of those systems have been put into commercial use. In most such systems, the inboard end of the belt remains stationary, thereby placing reliance entirely upon movement of the outboard end to move the belt to the release configuration. With such arrangements the part of the belt which extends across the occupant still remains quite close to his or her body, and the occupant ordinarily has to manually push the belt farther forward to be able to leave or enter the vehicle with ease.
In another type of passive belt system, which is often called a "three-point belt system," a continuous restraint belt is attached at one end to the upper rear corner of the door and at the other end to the lower rear corner of the door, and a control ring through which the restraint belt passes is attached to a control belt leading from a retractor on the inboard rear portion of the seat. The control belt is pulled out when the door is opened and pulled in when the door is closed. Although the restraint belt is moved some distance forward when the door is open, thus partially releasing the occupant, the control belt still obstructs convenient entry or departure, even in systems in which the outboard end of the lap belt portion of the restraint belt is transferred forwardly and upwardly along the door by a movable belt transfer guide.
Japanese Utility Model Publication No. 48511/77 describes and shows a seat belt system which includes a guide rail installed on the upper surface of a center console between the driver and passenger seats in front of the passenger compartment, and an occupant restraint belt leads through a guide ring mounted on a slider which moves forward and backward along the guide rail. While this construction is useful in vehicles which have a center console, it is not useful in vehicles which do not have them.